Grinding-mill.



B. G. GRIFFIN, DEGD.

L. M. GRIFFIN, BXEUUTRIX.

V GRINDING MILL.

APPLICATION FILED JULY 25,1911.

Patented Mar. 12, 1912.

r nnnn lr l l I l l l l A l u l l nl STATES PATENT OFFTCE.

EDWIN C. GRIFFIN, OF NEWTON, MASSACHUSETTS; LOVINA M. GRIFFIN, EXECUTRIXOF SAID EDWIN C. GRIFFIN, DEGEASED, ASSIGNOR TO BRADLEY PULVERIZER COM-PANY, OF BOSTON, MASSACHUSETTS7 A CORPORATION 0F MAINE.

GRINDING-MILL.

To all whom 'it 'may concern.'

Be it known that I, EDWIN C. GRIFFIN, a subject of the King of GreatBritain, residing at Newton, in the county of Middlesex and State ofMassachusetts, have invented 4certain new and useful Improvements inGrinding-Mills, of which the following is a specification, referencebeing had to the accompanying drawings, forming part thereof.

This invention has reference to improvements in mills for pulverizing orgrinding slag, ore, rock, or similar material preferably ground in a drycondition, and the invention relates more particularly to that class ofsuch grinding mills in which the grinding is effected by a roll having agyratory action with relation to its suspension mechanism which rollcoperates with an annular die.

One object of the invention is to so mount the sustaining bearing forthe suspension mechanism of the grinding roll shaft that said bearing islocated above the driving pulley and above the dust rising from the millwhile said bearing is located at a point at which it .may beconveniently accessible.

Another object of this invention is to so construct a grinding millhaving a rotary driving and suspension mechanism for the shaft of 'thegrinding device and a gyratory shaft carried by said mechanism that saidsuspension mechanism may operate a fan which will not interfere withgyratory movement of the grinding roll shaft. The current of air createdby said fan being confined and directed toward the axis about which thegrinding device swings.

Other objects of the invention will appear from the followingdescription.

The invention consists in the peculiar construction of the sustainingbearing for the rotary suspension mechanism of the grinding device.

The invention also consists in the combination with the rotarysuspension mechanism of the gyratory grinding roll shaft carried by suchmechanism, the rotary fan embracing the path of said shaft withoutrestricting the operation thereof, and the air chamber or drum embracingsaid fan and, preferably, having an outlet of less diameter than that ofthe annular grinding die and of the screen.

The invention also consists in such other Specification of LettersPatent.

Application filed July 25, 1911.

Patented Mar. 12, 1912.

serial No. 640,413.

novel features of construction and combination of parts as shallhereinafter be more fully described and pointed out in the claims.

Figure 1, represents a side elevation, partly in vertical section, ofthe improved grinding mill. Fig. 2, represents a sectional view of thesame taken on line 2*2 Fig. 1. Fig. 3, represents a view of the fanpartially in elevation and partially in section as on line 3 3 Fig. 2.

Similar numbers of reference designate corresponding parts throughout.

As shown in the drawings, in its preferred form, 5 indicates the base orbody of the mill having the pan 6 furnished with the annular die 7 abovewhich is located the annular screen 8 and the annular casing drum 9which embraces the screen S at a distance therefrom to provide a chambera, in which the pulverized material is received after such materialpasses through said screen. The upper end of chamber a is closed by thecap ring or plate 10, which extends inward to a point within the screen8 and has a central opening which is embraced by the depending lip 11 ofsaid plate 10, which lip is adapted to receive the collar l2. Plate 10is sustained from portions of the main frame by bolts as 1S and saidplate supports the fan chamber 14;.

The frame of the machine comprises the members 15, 15 and 16, 16preferably as shown. On the members 15, 15 is mounted the annular member17 provided with the ring 18 and securing means for said ring, the innersurface of said member 17 and ring being curved to form a seat in whichbearing 19 can be adjustably secured. Frame lncmbers 16, 16 at theirupper ends support the cross piece 20 having the seat 21 curved andcontracted at its lower portion, in which seat is adjustably secured theglobular exterior of the bearing box 22.

Bearing box 22 has a vertical bore and the upper chamber 23, which isclosed by the cap 241. Vithin this chamber 23 is located the bearingring 25 for antifriction bearing members as 26 which support the nut 27secured to the shaft 27 which latter extends through and is journaled inthe bore of the bearing box 22 and at its lower enlarged end is securedin the hub 28 of drive pulley 29 from which hub depends the hollow shaftmember 30 having the spreading mouth' 31, extending into the fan chamber14, and the shoulder32 provided with the bearing ring 33. On the mouth31 of said hollow shaft member 30 is clamped the two part frame 34having a series of fan blades 35, 35.

Ring 33 forms the direct suspension member on which the convex lowerface 36 of the head 37 may swing, while rotation of said head 37 iseifected by the engagement of its cross head 38 between the cheeks 39,39 of the rotary hollow shaft member 30. Secured in the head 37 is theshaft 40 having at its lower end the roll 41 which under theVcentrifugal act-ion of the lower end of shaft 40 under the rotary motionof the casing 30 may ride against the inner surface of the die 7.

Provision is made to feed material to be ground through the feedingmechanism indicated as a whole by numeral 42 and to deliver suchmaterial at a point within the screen 8 and below the opening of the fanchamber 14.

It is to be noticed that the pulley 29 is located approximately midwaybetween the bearings 19 and 22, whereby power is delivered at a mosteective point and the grinding shaft suspension mechanism, includingshaft 27 to the depending mouth 31 of the hollow shaft member 30, issustained by the antifriction bearing contained in chamber 23. When saidpulley 29 is rapidly rotated the fan blades 15 operate to create adownward current of air within the air chamber 1'4, and this current ofair flows down through the contracted opening 11 having the collar 12 toa point within the centrifugal grinding path of the grinding roll 41 andthen outward through the screen S carrying with it some portions of theground material which are sufliciently small to pass through the meshesof the screen. The air currents alsoprevent the rising of the dustthrough said air chamber.

Having thus describedA my invention, I claim as new and desire to secureby Letters Patent.

1. A grinding mill of the nature described ccmprising a frame having atits upper end a concave seat, a bearing member having a globularperiphery adjustable in said seat, a ring supported by said bearingmember, a shaft journaled in said bearing member and having a nut at itsupper end, antifriction devices on said ring for supporting said nut,a'hollow shaft member mounted on the lower end of said shaft and havinga pulley, a bearing in which the lower portion of said hollow shaftmember is journaled, and a grinding roll shaft pivotally mounted withinsaid hollow shaft member, as described.

2. A grinding mill of the nature described comprising a pan having anannular die, a screen embracing said die, a casing drum inclosing saidscreen, a fan casing located above the screen and having an outletextending within the screen, a hollow shaft rotatably mounted andextending into said fan chamber, a fan on the lower end of said hollowshaft, and a roll shaft mounted in said hollow shaft for gyrat-orymovement and having at its free end a Vgrinding roll adapted to coperatewith said annular die.

3. A grinding mill of the nature described comprising a pan having anannular die, a screen embracing said die, a casing drum inclosing saidscreen, a cap plate eX- tending inward from said casing drum and havinga contracted opening of less diameter than said screen and furnishedwith a depending collar, a fan chamber located on said cap plate, a fanrotatably mounted in said fan chamber, means for operating said fan, anda gyratory grinding device coperating with said annular die,substantially as described.

4. A grinding mill of the nature described comprising a pan having anannular die, a screen embracing said die, a casing drum inclosing saidscreen, a cap plate for said casing drum and screen having a contractedopening, a fan chamber mounted on said plate, a frame having at itsupper end a seat, a bearing member mounted in Said seat and furnishedwith an antifriction bearing, a shaft journaled insaid member and havingmeans for engaging said antifriction bearing, a hollow shaft membermounted at the lower end of said shaft and having a pulley and a mouthdepending below said pulley,'a bearing in which said hollow shaft memberis journaled, a fan on the mouth of said shaft member and located insaid fan casing, and a shaft having its upper end mounted in said hollowshaft member for universal movement and furnished at its EDWIN C.GRIFFIN.

Witnesses:

FRED M. MONTGOMERY, HENRY J. MILLER.

Copies of this patent may be obtained for ve cents each, by addressing'the Commissioner of Patents, Washington, D. C.

